There is a tremendous need for a reliable, accurate, and fast acting means for detecting potentially dangerous nuclear materials. Currently, there is a lack of suitable neutron detectors to screen for hidden nuclear devices. Neutron detection is a preferred radiation detection technique because the detection of neutrons is very selective toward threats. There are only two terrestrial sources of neutrons: (1) particle accelerators with suitable targets; and (2) fissile materials. Particle accelerators are immobile, therefore detection of neutrons from a container means fissile material. Fissile materials form two threats. One is as a nuclear weapon, the other as a “dirty bomb”, a source of highly radioactive contamination. The only valid source of neutrons would be a source for medical use, which is clearly marked and its transport is heavily regulated.